The ggtext package provides various functions to add formatted text to ggplot2 figures, both in the form of plot or axis labels and in the form of text labels or text boxes inside the plot panel. Text formatting can be achieved through a small subset of markdown, HTML, and CSS directives. Features currently supported include italics, bold, super- and sub-script, as well as changing font size, font family, and color. Basic support for adding images to formatted text is also available.
Claus Wilke is Professor of Integrative Biology at The University of Texas at Austin. He holds a PhD in Theoretical Physics from the University of Bochum in Germany, and he received postdoctoral training in biological physics in the lab of Chris Adami at Caltech. Claus Wilke has published extensively on the topics of computational biology and molecular evolution, and he is an author or contributor to several widely used R packages for data visualization, including cowplot, ggridges, colorspace, and ggplot2.